<?php
/**
 * Zend Framework
 * LICENSE
 * This source file is subject to the new BSD license that is bundled
 * with this package in the file LICENSE.txt.
 * It is also available through the world-wide-web at this URL:
 * http://framework.zend.com/license/new-bsd
 * If you did not receive a copy of the license and are unable to
 * obtain it through the world-wide-web, please send an email
 * to license@zend.com so we can send you a copy immediately.
 * @category Zend
 * @package Zend_Db
 * @subpackage Statement
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 * @version $Id: Db2.php 24625 2012-02-22 21:53:40Z adamlundrigan $
 */
/**
 *
 * @see Zend_Db_Statement
 */
require_once 'Zend/Db/Statement.php';

/**
 * Extends for DB2 native adapter.
 * @package Zend_Db
 * @subpackage Statement
 * @copyright Copyright (c) 2005-2012 Zend Technologies USA Inc. (http://www.zend.com)
 * @license http://framework.zend.com/license/new-bsd New BSD License
 */
class Zend_Db_Statement_Db2 extends Zend_Db_Statement {

    /**
     * Column names.
     */
    protected $_keys;

    /**
     * Fetched result values.
     */
    protected $_values;

    /**
     * Prepare a statement handle.
     * @param string $sql
     * @return void
     * @throws Zend_Db_Statement_Db2_Exception
     */
    public function _prepare ($sql) {
        $connection = $this -> _adapter -> getConnection ();
        // db2_prepare on i5 emits errors, these need to be
        // suppressed so that proper exceptions can be thrown
        $this -> _stmt = @db2_prepare ($connection, $sql);
        if ( ! $this -> _stmt) {
            /**
             *
             * @see Zend_Db_Statement_Db2_Exception
             */
            require_once 'Zend/Db/Statement/Db2/Exception.php';
            throw new Zend_Db_Statement_Db2_Exception (db2_stmt_errormsg (), db2_stmt_error ());
        }
    }

    /**
     * Binds a parameter to the specified variable name.
     * @param mixed $parameter Name the parameter, either integer or string.
     * @param mixed $variable Reference to PHP variable containing the value.
     * @param mixed $type OPTIONAL Datatype of SQL parameter.
     * @param mixed $length OPTIONAL Length of SQL parameter.
     * @param mixed $options OPTIONAL Other options.
     * @return bool
     * @throws Zend_Db_Statement_Db2_Exception
     */
    public function _bindParam ($parameter, &$variable, $type = null, $length = null, $options = null) {
        if ($type === null) {
            $type = DB2_PARAM_IN;
        }
        if (isset ($options['data-type'])) {
            $datatype = $options['data-type'];
        } else {
            $datatype = DB2_CHAR;
        }
        if ( ! db2_bind_param ($this -> _stmt, $parameter, "variable", $type, $datatype)) {
            /**
             *
             * @see Zend_Db_Statement_Db2_Exception
             */
            require_once 'Zend/Db/Statement/Db2/Exception.php';
            throw new Zend_Db_Statement_Db2_Exception (db2_stmt_errormsg (), db2_stmt_error ());
        }
        return true;
    }

    /**
     * Closes the cursor, allowing the statement to be executed again.
     * @return bool
     */
    public function closeCursor () {
        if ( ! $this -> _stmt) {
            return false;
        }
        db2_free_stmt ($this -> _stmt);
        $this -> _stmt = false;
        return true;
    }

    /**
     * Returns the number of columns in the result set.
     * Returns null if the statement has no result set metadata.
     * @return int The number of columns.
     */
    public function columnCount () {
        if ( ! $this -> _stmt) {
            return false;
        }
        return db2_num_fields ($this -> _stmt);
    }

    /**
     * Retrieves the error code, if any, associated with the last operation on
     * the statement handle.
     * @return string error code.
     */
    public function errorCode () {
        if ( ! $this -> _stmt) {
            return false;
        }
        $error = db2_stmt_error ();
        if ($error === '') {
            return false;
        }
        return $error;
    }

    /**
     * Retrieves an array of error information, if any, associated with the
     * last operation on the statement handle.
     * @return array
     */
    public function errorInfo () {
        $error = $this -> errorCode ();
        if ($error === false) {
            return false;
        }
        /*
         * Return three-valued array like PDO. But DB2 does not distinguish between SQLCODE and native RDBMS error code, so repeat the SQLCODE.
         */
        return array($error, $error, db2_stmt_errormsg ());
    }

    /**
     * Executes a prepared statement.
     * @param array $params OPTIONAL Values to bind to parameter placeholders.
     * @return bool
     * @throws Zend_Db_Statement_Db2_Exception
     */
    public function _execute (array $params = null) {
        if ( ! $this -> _stmt) {
            return false;
        }
        $retval = true;
        if ($params !== null) {
            $retval = @db2_execute ($this -> _stmt, $params);
        } else {
            $retval = @db2_execute ($this -> _stmt);
        }
        if ($retval === false) {
            /**
             *
             * @see Zend_Db_Statement_Db2_Exception
             */
            require_once 'Zend/Db/Statement/Db2/Exception.php';
            throw new Zend_Db_Statement_Db2_Exception (db2_stmt_errormsg (), db2_stmt_error ());
        }
        $this -> _keys = array();
        if ($field_num = $this -> columnCount ()) {
            for ($i = 0; $i < $field_num; $i ++ ) {
                $name = db2_field_name ($this -> _stmt, $i);
                $this -> _keys[] = $name;
            }
        }
        $this -> _values = array();
        if ($this -> _keys) {
            $this -> _values = array_fill (0, count ($this -> _keys), null);
        }
        return $retval;
    }

    /**
     * Fetches a row from the result set.
     * @param int $style OPTIONAL Fetch mode for this fetch operation.
     * @param int $cursor OPTIONAL Absolute, relative, or other.
     * @param int $offset OPTIONAL Number for absolute or relative cursors.
     * @return mixed Array, object, or scalar depending on fetch mode.
     * @throws Zend_Db_Statement_Db2_Exception
     */
    public function fetch ($style = null, $cursor = null, $offset = null) {
        if ( ! $this -> _stmt) {
            return false;
        }
        if ($style === null) {
            $style = $this -> _fetchMode;
        }
        switch ($style) {
            case Zend_Db::FETCH_NUM :
                $row = db2_fetch_array ($this -> _stmt);
                break;
            case Zend_Db::FETCH_ASSOC :
                $row = db2_fetch_assoc ($this -> _stmt);
                break;
            case Zend_Db::FETCH_BOTH :
                $row = db2_fetch_both ($this -> _stmt);
                break;
            case Zend_Db::FETCH_OBJ :
                $row = db2_fetch_object ($this -> _stmt);
                break;
            case Zend_Db::FETCH_BOUND :
                $row = db2_fetch_both ($this -> _stmt);
                if ($row !== false) {
                    return $this -> _fetchBound ($row);
                }
                break;
            default :
                /**
                 *
                 * @see Zend_Db_Statement_Db2_Exception
                 */
                require_once 'Zend/Db/Statement/Db2/Exception.php';
                throw new Zend_Db_Statement_Db2_Exception ("Invalid fetch mode '$style' specified");
                break;
        }
        return $row;
    }

    /**
     * Fetches the next row and returns it as an object.
     * @param string $class OPTIONAL Name of the class to create.
     * @param array $config OPTIONAL Constructor arguments for the class.
     * @return mixed One object instance of the specified class.
     */
    public function fetchObject ($class = 'stdClass', array $config = array()) {
        $obj = $this -> fetch (Zend_Db::FETCH_OBJ);
        return $obj;
    }

    /**
     * Retrieves the next rowset (result set) for a SQL statement that has
     * multiple result sets.
     * An example is a stored procedure that returns
     * the results of multiple queries.
     * @return bool
     * @throws Zend_Db_Statement_Db2_Exception
     */
    public function nextRowset () {
        /**
         *
         * @see Zend_Db_Statement_Db2_Exception
         */
        require_once 'Zend/Db/Statement/Db2/Exception.php';
        throw new Zend_Db_Statement_Db2_Exception (__FUNCTION__ . '() is not implemented');
    }

    /**
     * Returns the number of rows affected by the execution of the
     * last INSERT, DELETE, or UPDATE statement executed by this
     * statement object.
     * @return int The number of rows affected.
     */
    public function rowCount () {
        if ( ! $this -> _stmt) {
            return false;
        }
        $num = @db2_num_rows ($this -> _stmt);
        if ($num === false) {
            return 0;
        }
        return $num;
    }

    /**
     * Returns an array containing all of the result set rows.
     * @param int $style OPTIONAL Fetch mode.
     * @param int $col OPTIONAL Column number, if fetch mode is by column.
     * @return array Collection of rows, each in a format by the fetch mode.
     *         Behaves like parent, but if limit()
     *         is used, the final result removes the extra column
     *         'zend_db_rownum'
     */
    public function fetchAll ($style = null, $col = null) {
        $data = parent::fetchAll ($style, $col);
        $results = array();
        $remove = $this -> _adapter -> foldCase ('ZEND_DB_ROWNUM');
        foreach ($data as $row) {
            if (is_array ($row) && array_key_exists ($remove, $row)) {
                unset ($row[$remove]);
            }
            $results[] = $row;
        }
        return $results;
    }

}
